Metallization of glass surface is widely used in various fields. An example of such glass is K-glass, which is a high-quality glass having a low-emissivity coating applied to one surface of the glass during its manufacture. Molecules of the metallized coating penetrate deep into the crystal lattice of glass, which makes it very stable, extremely mechanically strong and permanent. Coating obtained using this technology is referred to as “hard” coating.
Glass with low-emissivity coating is also known to be used for the manufacture of glass products with electrically heated surface.
In particular, a glass product with electrically heated surface is disclosed in GB 1051777 A. The technical solution is aimed at heating a glass having a non-rectangular shape, which is accomplished by providing a plurality of individual sections in an electroconductive layer, the sections being connected in groups of successive sections, which groups are connected in parallel in electric circuit.
However this solution has limited application since the division of surface into paired sections allows the attainment of the aim only in a glass product with uniformly changing shape, such as trapezoidal. Furthermore, the need to provide multiple connections between sections complicates the structure as a whole. Also, this solution does not allow heating glass with specified conditions of heating.
The most relevant prior art is described in application EA 201000722 A1, according to which a glass product with electrically heated surface comprises a substantially transparent substrate and a substantially transparent electroconductive layer applied to the substrate, wherein the electroconductive layer comprises one or more sections with a specified surface resistance increased relative to the total surface resistance of the electroconductive layer. In this application, sections with increased surface resistance are formed by figures applied as fragments of lines having predetermined configuration at an angle to each other in a predetermined sequence over the entire surface of glass. The figures are positioned with a predetermined pitch and have the same dimensions within one section of the electrically heated surface.
Basic disadvantages of this prior art include the appearance of heat emission concentration zones at the ends of the line fragments, which is a significant problem, and the fact that due to uncertain shape of the figures formed by angled lines the “pitches” of these figures cannot be accurately aligned in adjacent sections with different surface resistance, this resulting in appearance, between these areas, of zones whose resistance cannot be calculated.
Other disadvantages include the difficulty of calculating dimensions and configurations of the figures to provide the desired surface resistance and, accordingly, the technical complexity of this solution, in particular, the complexity of applying the line fragments.